LncRNA CASC15 regulates breast cancer cell stemness via the miR‐654‐5p/MEF2D axis

Emerging evidence has demonstrated the prognostic and diagnostic potential of long noncoding RNA (lncRNA) cancer susceptibility candidate 15 (lncRNA CASC15) for the progression and tumorigenesis of human cancer. However, how CASC15 modulates the stemness of breast cancer stem cells (BCSCs) is not well understood. In this study, high expression of CASC15 in MCF-7 CSCs was reported, relative to MCF-7 cells, and this phenomenon was associated with metastatic lymph nodes, higher TNM stage, and shorter breast cancer survival rates. Further experiments revealed that CASC15 promoted the acquisition of stemness properties of breast cancer cells (BSCCs) by competing with endogenous RNA for miR-654-5p, resulting in overexpression of MEF2D in BCSCs. Overall, breast cancer stemness and tumor development are regulated via the CASC15/miR-654-5p/MEF2D axis. Accordingly, this pathway can be explored for breast cancer therapy.